Key-operated chain door-lock construction

ABSTRACT

The invention contemplates a key-operated housing structure for chain door-lock mechanism, wherein a bolt at one end of the chain is releasably retained, subject to the control of the key. The bolt is enterable in a bore in the housing, and before reaching the home position, a recess in the bolt is dogged to a spring, which is otherwise normally in the path of movement of the inserted bolt. The key-operated means is directly engageable with the spring to relieve the dogged engagement of the bolt, and means coating between the spring and the housing assures that unauthorized attempted removal of the bolt will not impair the normal spring suspension and action.

Ti 0 w W mte tates 1 tent 51 3,64@,W6 Lorincz 1 Feb. 8, 1972 [54] KEY-OPERATED CHAIN DOOR-LOCK 2,966,053 12/1960 Mintz ..70l93 CONSTRUCTION 3,101,603 8/1963 North ....70/93 3,125,875 3/1964 Friedman ..70/93 [72] Inventor: Eugene M. Lorincz, Cmnammson, NJ.

73 Assignee: Wessel Hardware Corporation, Philadelphia' Attorney-Sandoe, Hopgood and Calimafde [22] Filed: Oct. 12, 1970 57 ABSTRACT PP N01 38 The invention contemplates a key-operated housing structure for chain door-lock mechanism, wherein a bolt at one end of the chain is releasably retained, subject to the control of the 8 key. The bolt is enterable in a bore in the housing, and before 58] Fie'ld 131 1 292/83 87 reaching the home position, a recess in the bolt is dogged to a 292/264 spring, which is otherwise normally in the path of movement of the inserted bolt. The key-operated means is directly engageable with the spring to relieve the dogged engagement of [56] References cued the bolt, and means coating between the spring and the hous- UNITED STATES PATENTS ing assures that unauthorized attempted removal of the bolt will not impair the normal spring suspension and action. 2,867,468 1/1959 Bugge ..292/264 2,896,988 7/ I959 Hitzelberger ..292/83 14 Claims, 10 Drawing Figures mcmEnmamz 3.640.106

SHEET 2 OF 2 W 22 WW w 0 NEYS KEY-OPERATED CHAIN DOOR-LOCK CONSTRUCTION This invention relates to a chain door-lock mechanism of the variety used to provide double assurance against unlawful entry into locked premises and wherein a chain connects a part on the door frame with a part on the door, the connection being severable by having a free end of the chain enter a slot to complete the connection. The invention is concerned particularly with such chain locks in which the other end of the chain is selectively detachable through the privileged access of key operation.

Chain locks of the character indicated have taken various forms in the past, but to applicants knowledge they have been unduly complex and require a succession of latching operations and movements to take place in order to establish the connection. They also require an unduly complex relation of parts for key actuation to remove the fastening, when desired. Because of this complexity, operation has not been as foolproof nor has the structure been as rugged as is desired. Moreover, the complexity gives rise to undue cost.

It is, accordingly, an object of the invention to provide an improved and more reliable device of the character indicated.

Another object is to provide a materially simplified and less costly structure of the character indicated which at the same time avoids mechanical difficulties of past constructions.

A further object is to provide a construction of the character indicated in which key operation and bolt-latching functions are accomplished by more direct means than heretofore.

Other objects and various further features of novelty and invention will be pointed out or will occur to those skilled in the art from a reading of the following specification in conjunction with the accompanying drawings. In said drawings, which show, for illustrative purposes only, preferred forms of the invention:

FIG. I is a view primarily in elevation but partly in perspective to show an overall chain-lock assembly to a door and door frame, in accordance with the invention;

FIG. 2 is a front view in elevation of the key-operated structural component of FIG. 1;

FIG. 3 is a sectional view, taken generally at the plane 3--3 of FIG. 2;

FIG. 4 is a view in elevation of the backside of the structure of FIG. 2;

FIG. 5 is an enlarged view in section, taken at the plane 5- 5 of FIG. 2;

FIG. 6 is an enlarged fragmentary perspective view to illustrate a modified part of the combination of the invention;

FIG. 7 is a sectional view taken at the alignment 7-7 of FIG. 6;

FIGS. 8 and 8A are enlarged perspective views to illustrate an optional additional part and its subassembly to one of the parts of FIGS. 3 to 5; and

FIG. 9 is a perspective view to illustrate a further modificatron.

Briefly stated, the invention contemplates a key-operated housing structure wherein the bolt at the end of a chain lock of the character indicated is releasably retained, subject to the control of the key. The bolt is enterable in a bore in the housing, and before reaching the home position, a recess in the bolt is dogged to a spring, which is otherwise normally in the path of movement of the inserted bolt. The key-operated means is directly engageable with the spring to relieve the dogged engagement of the bolt, and means coacting between the spring and the housing assures that unauthorized attempted removal of the bolt will not impair the normal spring suspension and action.

In FIG. 1 of the drawings, the invention is shown in application to the selectively controlled locking of movement as between a door 10 and a doorframe 11. A chain 12 is selectively fastenable at each of its ends to structure 13, carried by the door, and to structure 14, carried by the doorframe; however, it will be understood that the mounting of these structures may be reversed, as dictated by particular installation requirements.

The fastening unit 13 comprises a frame with separate means 15 for securing the same to the door. The frame has an elongated slot 16 with an enlargement at the end remote from the door edge, for selective removable reception of the head of a pin 17 at the corresponding end of the chain 12.

The fastening means 14 for the other end of the chain 12 comprises a housing 19 with means 20 for securing the same to the doorframe 11. The housing includes a bore on the trans verse axis 21 along which a bolt 22, carried at the end of the chain 12, is longitudinally enterable. Spring means of the invention, within the housing 14, engages and dogs the bolt 22 (at a recessed portion 22 thereof) when fully inserted, and it is necessary to resort to key operation at lock means 23 to dislodge the bolt 22. As shown, the face 24 of the housing 14, on which the key-operated means 23 is mounted and through which the bolt 22 is enterable, is also provided with an opening 25 by which the head of pin 17 may be engaged as desired when the chain lock is not to be used, thus keeping the chain clear of the door and free of door movement.

Referring to FIGS. 2 to 5 of the drawings, the structure of the housing 14 is seen to rely upon a single piece 19, which may be a metal casting, into which spaced bosses 26-26 are formed as part of sidewalls 2427, respectively. The bosses 26-26 have aligned bores for inserted reception of the bolt means 22. In the form shown, these bores are cylindrical, being identified at 29, for the case of the bore in the boss 26, and at 30, for the case of the bore in the boss 26. Between the bosses, the body of the housing 19 is excavated along a channel alignment, seen in section in FIG. 5 and identified generally 31; this channel alignment is generally transverse to the axis 21 of bore insertion. In the form shown, the boss 26 is substantially larger than the boss 26', and at the open end of bore 29 in the larger boss 26 there is a counterbore 32 for accommodation of preload-spring means 33 carried by and forming part of the bolt structure 22, as will be later explained.

In accordance with a feature of the invention, the inserted bolt means 22 is directly engaged by latch-spring means 34 to latch and hold the inserted position; the latch-spring means is carried and positioned by the housing in such manner that a resiliently deflectable portion thereof is normally positioned in the path of entering movement of the bolt within bores 2930, i.e., poised for engagement by a conical cam formation 22" at the nose end of bolt 22. The spring means 34 may be an elongated flat ribbon of spring steel, supported in the housing 19 on spaced pedestals at opposite sides of the bore alignment 21. The pedestals are formed at 35-36 within comers of the integral casting of the housing 19; this same casting includes at each such pedestal spaced ears or lugs 37-37 for the case of the pedestal 35, and 3838' for the case of the pedestal 36, to provide accurate lateral and longitudinal positioning location of the spring 34, i.e., to establish two widely spaced locating points of support of the same within the housing 19. The alignment of spring 34, when thus positioned, is in register with the channel 31, and theelevation of spring 34 is normally such as to pass through the alignment of bores 39-30 at a location radially offset from the central axis 21 thereof. This offset relation is identified d in FIG. 3.

As shown, the spring 34 has a cross section characterized by a width dimension W substantially exceeding a thickness direction T, and the full such cross section is relied upon at the location of pedestal support (3536) and at the location of passage through the channel 31, i.e., on both sides of the passage of 'the spring through the alignment of bores 2930. The width dimension W of the spring should be just less than the width of the channel 31 to allow for free spring deflection between the spaced points of support at 35-36, and the width dimension W of the spring should extend substantially parallel to the bore axis 21. The described proportions, orientation and location of the central full-width section of spring 34 presents utmost strength in shear, frame-referenced at the bossed region, to foil unauthorized attempts to remove bolt 22.

As seen best in FIG. 4, ease of resilient action for an otherwise stiff spring 34 is achieved by cutting away a substantial part of the width dimension of the spring on opposite sides of its passage through the region of bosses -26. Thus, a first cutout portion on one side of the region of passage between the bosses, and an oppositely cutout portion 41 on the other side of the region of passage between the bosses, enable spring deflection to be primarily located in such regions outside that of the bosses 25-26. Since the cutout portions 40-41 are oppositely offset, the cam engagement (by nose 22" at the central region of spring 34, upon bolt insertion) serves essentially only to lift the central region of spring 34 until the latter registers with and snaps with latch action into the bolt recess 22,

As shown, the key-operated means 23 is a pin-tumbler cylinder lock having a crank pin 42, normally positioned as seen in FIG. 3, i.e., poised at the 6 oclock position, to thereby lightly retain spring 34, and in readiness for key-operated actuation to the 9 0clock position. In the course of such actuation, pin 42 engages and resiliently deforms spring 34, displacing the wide central region thereof out of the recessed position 22' of the bolt, and thus releasing the bolt 22 for removal.

For a more solid (i.e., rattle free) feel as latch spring 34 snaps into recess 22', I prefer that a resilient axial preload shall have been established for bolt 22, at its latch position. In FIG. 5, such preload is seen to be accomplished by a coil spring 33 having a radially inward formation at one end, for snap-in location in a retaining groove 43 in bolt 22; alternatively, the numeral 43 may identify a radially outward bead, to engage and axially locate the last turn of the coil spring 33. In the unstressed condition, coil spring 33 may axially extend slightly greater than the depth of counterbore 32, so that an axial preload develops just before latch spring 34 snaps into recess 22, and coil spring 33 is minimally exposed when the bolt 22 is latched.

In the modification of FIG. 6, the bolt 45 is similarly formed with a latch recess 46 between its cam nose 47 and body 48, to fit the bore 29. The body 48 also has a peripheral retaining groove 49, but the spring means retained thereby is a washer 50 cut and formed from sheet spring stock. The spring washer 50 has angularly spaced inward lugs 51 to locate in groove 49, and between lugs 51 the washer undulates with angularly spaced axial projections 52. The length of body 48, in relation to the axial extent of washer undulation and depth of counterbore 32, is such that preload begins to develop as bolt shoulder 53 and the bottom of counterbore 32 compress washer 50, just prior to spring-latch action at 34-22, as previously described.

FIG. 8 illustrates an optional modification wherein a shoe 55 (FIG. 8A), preferably injection-molded of a suitable plastic having low friction properties, such as polyethylene, polypropylene, etc., is carried by spring 34 is the region of bosses 26-26' to give further assurance of free spring latch action. Shoe 55 has a generally rectangular prismatic body 56 of width W slightly exceeding the width W of spring 34. Diagonally opposed retaining lugs 57-57 enable preassembly to spring 34 at the adjacent inside comers of cutouts 40-41, merely by simple counterclockwise displacement, in subassembled relation, opposed edges of shoe 55 project slightly beyond the corresponding opposed edges of spring 34. Once thus subassembled, the spring 34 (with shoe 55) is inserted in the channel 31, and retention is permanent. A cutout 58 along the inner edge of shoe 55 assures nonfouling cam and latch action with the inserted bolt nose 22", as already described.

The modification of FIG. 9 illustrates that the functions of both springs 33-34 may be achieved by a single part 60. The part 60 may have essentially the same planform as the spring 34, with oppositely offset cutouts 40-41 as previously described. However, at the near end an integral upstanding flange or bend 61 provides the base for cantilevered support of another flat leaf or arm 62, extending normally generally parallel to the body 63, but in a plane normal to the plane of body 63. The free end of arm 62 is preferably aligned with the bolt axis 21, and the adjacent boss 26' is cutaway or recessed as necessary to accommodate resilient deflection of arm 62 in the course of bolt insertion. Full insertion is accompanied by latch engagement of the main spring body 63. If desired, the shoe 55 of FIG. 8A may be subassembled to the spring means of FIG. 9, in the manner described in connection with FIG. 8.

The invention will be seen to have accomplished the stated objects with utmost simplicity of action and low cost of construction, without sacrifice of the ruggedness needed for personal security.

While the invention has been described in detail for preferred forms, it will be understood that modifications may be made without departing from the invention.

I claim:

1. A key-operated chain lock comprising a chain including means at one end for selective fastening to door structure and means at the other end for selective fastening to a doorframe structure, one of said fastening means comprising a housing including means for mounting the same to one of said structures, said housing having a bore open to one side, an elongated bolt connected to the adjacent end of said chain and selectively enterable in said bore, said bolt having a peripheral recess in that part thereof which is overlapped by said bore when inserted therein, an elongated spring retained within said housing in such orientation that a resiliently deflectable portion of said spring is normally positioned in said bore and in the path of movement of said bolt, said deflectable portion being so longitudinally positioned in said bore that said deflectable portion will align with the bolt recess when said bolt is fully inserted in the bore, said bolt having at its bore-entering end a cam formation so located with respect to the bolt axis as to engage under and deflect said deflectable spring portion out of the path of bolt movement until such displacement of said bolt as will place said recess in spring-receiving alignment, and key-operated means carried by said housing and having deflecting engagement with said deflectable spring portion to displace the same out of said recess, whereby upon key operation, said bolt may be cleared of spring engagement for removal from said housing.

2. A lock according to claim 1, in which said bolt and bore are cylindrical, said recess being a circumferential groove.

3. A lock according to claim 1, in which said spring is an elongated leaf of spring ribbon.

4. A lock according to claim 3, in which said spring leaf is supported in said housing on both sides of the bore, said bolt and said key-operated means being engageable with said spring intermediate the spaced locations of support thereof.

5. A lock according to claim 1, in which said key-operated means is a cylinder lock with a key-rotatable crank pin having the deflecting engagement with said spring.

6. A lock according to claim 3, in which the section of said ribbon is characterized by a width dimension substantially exceeding a thickness dimension, and in which spring is oriented with the width dimension substantially parallel to the axis of the bore.

7. A lock according to claim 2, in which said cam formation is generally conical about the bolt axis, and in which the deflectable spring portion poised for engagement thereby is offset from said axis.

8. A lock according to claim 6, in which said housing includes abutment means adjacent to the width limits of said spring and adjacent both sides of the bore, whereby attempted bolt removal without key actuation will be denied by action at said abutment means, thereby relieving the spring-suspension connections to said housing from subjection to strain upon attempted bolt removal.

9. A lock according to claim 2, in which said housing has a counterbore near the bolt-insertion end of said bore, and axially acting spring means coacting between said bolt and housing and within the counterbore and axially stressed when said spring is engaged at the bolt recess.

10. A lock according to claim 9, in which said last-defined spring means is a coil spring carried by said bolt coaxially with the bolt axis.

11. A lock according to claim 9, in which said last-defined means is an annulus of resilient sheet metal carried by said bolt, said annulus having resiliently deflectable angularly spaced axial undulating projections engageable with said housing in the counterbore prior to spring engagement with the bolt recess.

12. A lock according to claim 6, and including a low-friction shoe member carried by the side of said ribbon which is opposite the side engaging said cam formation, said shoe member projecting laterally beyond at least one of the lateral edges of said ribbon.

13. A lock according to claim 12, in which said ribbon is cally recessed with an edge cutout which is offset from the region of bolt engagement, and in which said shoe includes retaining means in said cutout region and engaged to said ribbon.

14. A lock according to claim 1, in which said spring includes two integrally related leaves of spring ribbon extending substantially parallel to each other from their integral connection, one of said leaves being characterized by a width dimension substantially exceeding a thickness dimension, with the width dimension of said one leaf oriented substantially parallel to the axis of the bore; the other of said leaves being characterized by a width dimension substantially exceeding a thickness dimension, with the width dimension of said other leaf oriented substantially normal to and in the alignment of the bore. 

1. A key-operated chain lock comprising a chain including means at one end for selective fastening to door structure and means at the other end for selective fastening to a doorframe structure, one of said fastening means comprising a housing including means for mounting the same to one of said structures, said housing having a bore open to one side, an elongated bolt connected to the adjacent end of said chain and selectively enterable in said bore, said bolt having a peripheral recess in that part thereof which is overlapped by said bore when inserted therein, an elongated spring retained within said housing in such orientation that a resiliently deflectable portion of said spring is normally positioned in said bore and in the path of movement of said bolt, said deflectable portion being so longitudinally positioned in said bore that said deflectable portion will align with the bolt recess when said bolt is fully inserted in the bore, said bolt having at its bore-entering end a cam formation so located with respect to the bolt axis as to engage under and deflect said deflectable spring portion out of the path of bolt movement until such displacement of said bolt as will place said recess in spring-receiving alignment, and key-operated meaNs carried by said housing and having deflecting engagement with said deflectable spring portion to displace the same out of said recess, whereby upon key operation, said bolt may be cleared of spring engagement for removal from said housing.
 2. A lock according to claim 1, in which said bolt and bore are cylindrical, said recess being a circumferential groove.
 3. A lock according to claim 1, in which said spring is an elongated leaf of spring ribbon.
 4. A lock according to claim 3, in which said spring leaf is supported in said housing on both sides of the bore, said bolt and said key-operated means being engageable with said spring intermediate the spaced locations of support thereof.
 5. A lock according to claim 1, in which said key-operated means is a cylinder lock with a key-rotatable crank pin having the deflecting engagement with said spring.
 6. A lock according to claim 3, in which the section of said ribbon is characterized by a width dimension substantially exceeding a thickness dimension, and in which spring is oriented with the width dimension substantially parallel to the axis of the bore.
 7. A lock according to claim 2, in which said cam formation is generally conical about the bolt axis, and in which the deflectable spring portion poised for engagement thereby is offset from said axis.
 8. A lock according to claim 6, in which said housing includes abutment means adjacent to the width limits of said spring and adjacent both sides of the bore, whereby attempted bolt removal without key actuation will be denied by action at said abutment means, thereby relieving the spring-suspension connections to said housing from subjection to strain upon attempted bolt removal.
 9. A lock according to claim 2, in which said housing has a counterbore near the bolt-insertion end of said bore, and axially acting spring means coacting between said bolt and housing and within the counterbore and axially stressed when said spring is engaged at the bolt recess.
 10. A lock according to claim 9, in which said last-defined spring means is a coil spring carried by said bolt coaxially with the bolt axis.
 11. A lock according to claim 9, in which said last-defined means is an annulus of resilient sheet metal carried by said bolt, said annulus having resiliently deflectable angularly spaced axial undulating projections engageable with said housing in the counterbore prior to spring engagement with the bolt recess.
 12. A lock according to claim 6, and including a low-friction shoe member carried by the side of said ribbon which is opposite the side engaging said cam formation, said shoe member projecting laterally beyond at least one of the lateral edges of said ribbon.
 13. A lock according to claim 12, in which said ribbon is locally recessed with an edge cutout which is offset from the region of bolt engagement, and in which said shoe includes retaining means in said cutout region and engaged to said ribbon.
 14. A lock according to claim 1, in which said spring includes two integrally related leaves of spring ribbon extending substantially parallel to each other from their integral connection, one of said leaves being characterized by a width dimension substantially exceeding a thickness dimension, with the width dimension of said one leaf oriented substantially parallel to the axis of the bore; the other of said leaves being characterized by a width dimension substantially exceeding a thickness dimension, with the width dimension of said other leaf oriented substantially normal to and in the alignment of the bore. 